公开(公告)号：US3676229A

公开(公告)日：1972-07-11

申请号：US3676229D

申请日：1971-01-26

Applicant: RCA CORP

Inventor： EINTHOVEN WILLEM GERARD ,  JETTER EVELYN SPETER ,  WHEATLEY CARL FRANKLIN JR

IPC: G01R31/26 ,  H01L21/66 ,  H01L29/10 ,  H01L7/44

CPC classification number: H01L22/14 ,  G01R31/2637 ,  G01R31/2644 ,  H01L22/00 ,  H01L22/20 ,  H01L29/1004 ,  Y10S148/085 ,  Y10S148/162

Abstract: A SEMICONDUCTOR WAFER HAS A UNIFORMLY THICK COLLECTOR LAYER THEREIN WITH A UNIFORMLY THICK BASE LAYER ADJACENT THE COLLECTOR LAYER. A PLURALITY OF EMITTER REGIONS ARE DIFFUSED INTO THE BASE LAYER FROM THE SURFACE. DURING EMITTER DIFFUSION, AN ANNULAR REGION OF THE SAME CONDUCTIVITY AS THE EMITTER REGIONS IS ALSO DIFFUSED INTO THE BASE LAYER TO SURROUND A PORTION OF THE BASE LAYER AT THE SURFACE. THE SHEET RESISTIVITY OF THE BASE LAYER BETWEEN THE ANNULAR REGION AND THE COLLECTOR LAYER IS DETERMINED, AND IF BELOW A DESIRED MINMUM, THE EMITTER AND ANNULAR REGIONS ARE FURTHER DIFFUSED.